"He had another good night, " Brette said. "He's doing fine. He's in a good frame of mind."

Brette, who exercised the colt daily for trainer Michael Matz, has been visiting Barbaro almost every day since the colt shattered his right hind leg at the Preakness Stakes on May 20.

Barbaro's condition was stable through Saturday, and Brette seemed more upbeat than he was last week.

"He was bright," Brette said. "He sort of at least had a bit of sparkle in his eye."

The 3-year-old colt has the painful and often fatal condition laminitis in his left hind leg, and 80 percent of his hoof wall was removed Wednesday.

Barbaro has casts on both rear limbs. The cast on the colt's right rear leg has been changed at least four times in the last two weeks. A smaller fiberglass cast to protect his left rear hoof was changed Saturday, and is likely to be changed again in the coming days.

On Saturday, Dr. Dean Richardson reported that Barbaro was in stable condition — four days after he said the colt had laminitis "as bad as it gets" and termed his chance of survival poor.

"His heart rate and pulse are normal, and his appetite is good," Richardson said Saturday in a statement issued by the University of Pennsylvania's New Bolton Center. "He continues to respond well, looks good and has a positive attitude."